The Daytime Gamma Leonids meteor shower
Key facts
- Peak
- around 25 August
- Active
- mid-August to mid-September
- Rate at peak (ZHR)
- uncertain; not visible by eye
- Speed
- about 23 km/s
- Radiant
- Leo (near Algieba, Gamma Leonis, close to the Sun in the sky)
- Parent body
- Unknown
Dates shift slightly from year to year. This year's peak is in the events calendar, and the meteor-shower planner shows how high the radiant climbs from where you live, night by night.
The Daytime Gamma Leonids are a weak, slow daytime shower of late August, listed in the international catalogue from radar surveys but hard to detect in practice.
The radiant. In late August the Sun is in Leo, and the radiant lies near Algieba, Gamma Leonis, in the Sickle, the curve of stars that forms the Lion's mane. It is only a short distance from the Sun in the sky, so it is above the horizon in daytime and cannot be watched by eye.
What we know. The shower was found by radar, which detects meteor trails day and night. Its meteoroids enter slowly, at about 23 kilometres per second, which means their orbits are close to Earth's in direction. Radio observers in recent decades have not always found it, and its activity is uncertain.
The parent. No parent body has been identified.
Not the Leonids. The famous Leonids of November also come from Leo, but they are a completely different stream from comet Tempel–Tuttle, meeting Earth head on at about 71 kilometres per second, three times faster. Many constellations host several unrelated showers at different times of year.
What to expect. Nothing by eye. By radio, possibly a small rise in echoes around 25 August.
How to observe. A radio receiver tuned to a distant transmitter just over the horizon records reflections from meteor trails at any hour. Long, continuous records are needed to show whether a weak daytime shower is present, because the number of sporadic meteors also changes with the time of day and the season. Amateur radio observers who keep running through late August help to settle whether this shower is active.
Viewing tips
- Use radio detection; the radiant is beside the Sun.
- Record continuously through August and September for comparison.
- Compare echoes at the same time of day across several days.
- Never look towards the Sun when observing near dawn.
- Return in November for the Leonids, a different shower from the same constellation.